A device for applying a treatment medium to a moving strip of material is known from German Patent 33 15 770 C2. In that device, an application beam extends perpendicular over a strip of carpet that forms a strip of material and is curved forward relative to it. The beam contains an application slit that opens towards the strip of material. A treatment medium, dye bath in the exemplary embodiment, is passed to the application slit by a plurality of feed pipes at locations distributed over the width of the strip of material. Below the strip of carpet, an elastic pillow, for example an inflatable pillow, is provided. The elastic pillow presses the strip of material against the application beam on both sides of the application slit. An equilibrium situation results via the force. In other words, it is not possible to set a pre-determined gap between the application beam and the contact pressure element. In particular, it is difficult, in view of the great width of strips of carpet (about 5 m), to keep the conditions uniform over the width of the gap.
This problem also exists in the device shown in U.S. Pat. No. 5,063,646. In that device, a strip of carpet, with the nap down, is passed over a housing supported in a machine frame. A feed pipe that extends across the width of the strip of material is arranged in the housing. The top of the feed pipe is aligned with the top of the housing. The housing supports the strip of carpet on both sides of the feed pipe, over a short distance. At the peak of the feed pipe, there are many small perforations, through which the dye bath penetrates from the feed pipe into the nap of the carpet. A roller that runs along with the strip of material, provides support on the back of the side opposite the exit region of the dye bath. The roller is mounted in pivot levers affixed at the rollers' ends, and can be adjusted relative to the exit region by pivoting these levers. The bearing blocks of the pivot levers are vertically adjustable in order to determine the gap width between the support roller and the exit region. Given the large width of the strip of carpet, uniformity of the situation in the gap over the entire width is difficult to achieve.